OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

Which of the following does NOT happen during meiosis?

1. DNA replication occurs once

2. Four haploid cells are created

3. Formation of diploid daughter cells

4. Genetic variation is introduced

The correct answer is: Formation of diploid daughter cells

During meiosis, the objective is to produce gametes, which are haploid cells. This process involves two key divisions: meiosis I and meiosis II. DNA replication occurs only once before meiosis begins, ensuring that each chromosome is duplicated, which is essential for the subsequent stages. As meiosis progresses, it results in the formation of four haploid cells through the division of a single diploid cell. This is significant as it reduces the chromosome number by half, preparing the cells for sexual reproduction. Additionally, meiosis introduces genetic variation through processes such as crossing over and independent assortment. These mechanisms shuffle genetic material and create unique combinations of genes, contributing to the diversity of offspring. The choice identifying the formation of diploid daughter cells is incorrect, as meiosis does not produce diploid cells. Instead, it results in haploid cells, crucial for maintaining the correct chromosome number across generations. Thus, the answer correctly identifies what does not happen during meiosis.